1. Field of the Invention
The present invention relates to a semiconductor device, and particularly relates to a configuration and a layout of a level shift circuit for converting a level of an input signal into a predetermined amplitude level.
2. Description of Related Art
Recently, an operating voltage of semiconductor devices has been reduced because of downscaling of semiconductor devices. Semiconductor devices thus generate an internal operating voltage VPERI lower than an external voltage VDD supplied from outside of the device and operate based on the internal operating voltage VPERI. Signals outputted from a semiconductor device to an external device are boosted from the internal operating voltage VPERI to the external voltage VDD and the boosted signals are outputted. A level shift circuit is used for such conversion of an external voltage into an internal operating voltage.
International Publication No. WO2004/040765 (see FIGS. 2, 16, and 17 of the publication) discloses a level shift circuit configured by a pair of P-channel transistors which are connected in a flip-flop manner, a pair of first N-channel transistors that respective transistors are serially connected to the P-channel transistors and an input signal is inputted, and a pair of second N-channel transistors that respective transistors are connected in parallel to the P-channel transistors and an input signal is inputted.